docs: def add_init_service_checks(nrpe, services, unit_name, immediate_check=True):
      """
      Add checks for each service in list
  
      :param NRPE nrpe: NRPE object to add check to
      :param list services: List of services to check
      :param str unit_name: Unit name to use in check description
      :param bool immediate_check: For sysv init, run the service check immediately
      """
      for svc in services:
          # Don't add a check for these services from neutron-gateway
          if svc in ['ext-port', 'os-charm-phy-nic-mtu']:
              next
  
          upstart_init = '/etc/init/%s.conf' % svc
          sysv_init = '/etc/init.d/%s' % svc
  
          if host.init_is_systemd():
              nrpe.add_check(
                  shortname=svc,
                  description='process check {%s}' % unit_name,
                  check_cmd='check_systemd.py %s' % svc
              )
          elif os.path.exists(upstart_init):
              nrpe.add_check(
                  shortname=svc,
                  description='process check {%s}' % unit_name,
                  check_cmd='check_upstart_job %s' % svc
              )
          elif os.path.exists(sysv_init):
              cronpath = '/etc/cron.d/nagios-service-check-%s' % svc
              checkpath = '%s/service-check-%s.txt' % (nrpe.homedir, svc)
              croncmd = (
                  '/usr/local/lib/nagios/plugins/check_exit_status.pl '
                  '-e -s /etc/init.d/%s status' % svc
              )
              cron_file = '*/5 * * * * root %s > %s\n' % (croncmd, checkpath)
              f = open(cronpath, 'w')
              f.write(cron_file)
              f.close()
              nrpe.add_check(
                  shortname=svc,
                  description='service check {%s}' % unit_name,
                  check_cmd='check_status_file.py -f %s' % checkpath,
              )
              # if /var/lib/nagios doesn't exist open(checkpath, 'w') will fail
              # (LP: #1670223).
              if immediate_check and os.path.isdir(nrpe.homedir):
                  f = open(checkpath, 'w')
                  subprocess.call(
                      croncmd.split(),
                      stdout=f,
                      stderr=subprocess.STDOUT
                  )
                  f.close()
                  os.chmod(checkpath, 0o644)